Gnss antenna with an integrated antenna element and additional information sources

ABSTRACT

An improved GNSS antenna having an integrated antenna element in combination with a plurality of built-in sources of additional data and/or a plurality of devices for receiving additional information for exchanging the information and transmission of GNSS signals from the antenna element to a GNSS receiver over a single RF cable.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation of U.S. patent application Ser. No.15/745,456, filed Jan. 17, 2018, which is a U.S. national stage filingof International Application No. PCT/RU2016/000250, filed Apr. 27, 2016,both of which are incorporated herein by reference in their entirety.

TECHNICAL FIELD

The present invention relates generally to Global Navigation SatelliteSystem (GNSS) antenna design and, more particularly, to a GNSS antennahaving an integrated antenna element in combination with a plurality ofbuilt-in sources and receivers of additional information for exchangingthe information and transmission of GNSS signals from the antennaelement to a receiver over a single RF cable.

BACKGROUND

A satellite navigation receiver can obtain a navigation solution (i.e.,positioning information) provided that the receiver has reliable signalreception from a number of GNSS satellites to which the receiver is incontact. Reliable signal reception it typically enabled only undercertain operating conditions, that is, an open sky environment whenthere are no obstacles to radio signals propagating from selectednavigation satellites to the receiver's antenna. Any antenna blockage bynatural or artificial obstacles (e.g., high trees with dense foliage,vertical walls of buildings, bridges, urban canyons, and structuralelements of moving vehicles with a mounted GNSS antenna, and so on) willdeteriorate the quality of signal reception. As such, the accuracy ofthese navigation solutions may suffer greatly including a full loss ofthe ability to accurately provide GNSS positioning in any way. If a GNSSreceiver is integrated in a vehicle control system, even short-term GNSSpositioning accuracy loss can result in a complete failure of thevehicle's control system and be unacceptable from at least a vehicleand/or human operator safety perspective.

A GNSS receiver with a single antenna measures coordinates and velocityvector components (to the extent the antenna is in motion) only for asingle conditional point, the so-called antenna phase center (PC). Ifthe GNSS antenna is fixed onto a body of a movable object, the measuredcoordinates and PC velocity are taken as coordinates and velocity ofthis movable object. As such, given the singular nature of the data, anyorientation measurements of the movable object using a single antennaGNSS receiver is impossible given the need for multiple coordinates(e.g., roll, yaw, pitch, etc.) to determine orientation.

To determine vehicle orientation using a GNSS system, two or moreantennas should be placed at different points on the vehicle body tomeasure their coordinates (one relative to the other) in the vehicle'sbody coordinate frame. In this way, orientation parameters can becalculated from simultaneous PC coordinate measurements of using asingle-antenna (or one multi-antenna arrangement) GNSS receiver. Itshould be noted that two antennas allow a further determination to bemade with respect to the vehicle's attitude (i.e., up to one turn aboutthe baseline—a line connecting the PC of both antennas). Further, fullorientation of the vehicle in the GNSS system can be determined by threeor more spaced antennas.

A well-known method of avoiding short-term interruptions in the qualityof navigation solutions is the multiplexing of a GNSS receiver and aninertial navigation system (INS). As will be appreciated, INS is capableof measuring coordinates, velocity and orientation of a vehicleirrespective of the availability (or unavailability) of any externalinformation. However, errors with INS-only measurements tend tocontinuously grow (e.g., increasing drift), and INS navigational data istypically used in a motion control system only during a limited timeperiod. A joint use of GNSS and INS allows for the correction of INSaccumulated errors over all measured parameters (i.e., coordinates,velocity vector components, and orientation parameters). In thisGNSS-INS joint operation, GNSS measurements are used for the eliminationof potentially continuously growing INS errors for those vehicletrajectory paths for which GNSS solutions are fully accessible. Duringthese paths, the INS solution typically has acceptable errors and needsno additional correction. At the beginning of the trajectory paths wherethere exist poor GNSS conditions (i.e., the GNSS solution itself isunacceptable) or has short-time accuracy degradation, the INS solutionwill still have acceptable errors with these errors most likelyincreasing over time. If the GNSS interruption is short in relation tothe INS error growth the INS-only solution may be used to continue theentire navigation solution over this short time GNSS degradationinterval. In addition, a continuous correction of INS errors with GNSSmeasurements enables full vehicle orientation to be determined even incase of single-antenna GNSS receiver. When INS is multiplexed with adual-antenna GNSS system, INS measurements make it possible topermanently determine a rotation angle about the baseline which isimpossible for a single dual-antenna system.

A key element of INS is the use of a well-known inertial measuringmodule (IMU). An IMU consists of a set of inertial sensors (e.g., gyrosand accelerometers) rigidly fixed to a common base. A three-dimensionalvector basis called an IMU Measurement frame (MF) is associated with thecommon base and the sensitivity axes of the separate sensors have aconstant orientation relative to the MF. As will be understood, thecoordinates, velocity vector components, and orientation measured by theINS are MF origin coordinates, MF origin velocity components and MF axesorientation, respectively.

In order to successfully multiplex the INS and GNSS receiver, theantenna's PC coordinates relative to MF should be equal to the pre-setvalues over the whole period of servicing of the multiplexed system.Further, the origin of MF coordinates needs to be as close to theantenna element's PC as possible. For example, an arrangement having theIMU inside the antenna housing typically satisfies these requirements,and PC coordinates with respect to MF origin can be determined at thedesign stage of a combined housing for the IMU and antenna.

If any information about physical parameters in proximity to the PC isused in the algorithms of the receiver, sensors of these parameters maybe also located inside of the antenna housing. An example of suchsensors are magnetic field vector component sensors or atmosphericsensors which measure pressure, humidity level, and ambient temperaturedirectly at the point of receiving a GNSS signal.

In a GNSS navigation system in which the GNSS antenna and GNSS receiverare single modules connected by a RF cable, the distance between theantenna and receiver is limited by signal fading within the RF cableitself and having a range in the area of a few tens of meters. To usemeasurements from antenna sensors in signal processing algorithms, theyneed to be sent from the antenna to the receiver, and the measurementstaken from all the antenna sensors need to be related to the receiver'stime scale (i.e., the same time scale as that of the operatingalgorithms). This typically requires the transmission of asynchronization signal from the GNSS receiver to the GNSS antenna whichcan bind the moments of sampling of sensors and receivers in terms ofthe applicable time scale.

Processing a navigational signal received by a GNSS antenna necessarilyrequires the consideration of various antenna characteristics. As such,a single GNSS receiver capable of connecting different type antennasneeds to determine antenna type and obtain numerical values of antennaparameters. This may be facilitated by reading, just after the antennahas been connected, such numerical values from a memory (e.g.,non-volatile memory) resident inside the antenna. In addition, areceiver's firmware must have the capability of adjusting/reprogrammingsensors and/or the non-volatile memory module inside the antenna. Thismeans that a two-way information transfer channel is required betweenthe antenna and receiver.

One solution of addressing two-way data exchange between an antenna andreceiver is employing an additional cable through which the informationis transmitted according to any well-known digital communicationprotocol. In this case, the antenna and receiver are connected by twocables: one RF cable to transmit GNSS signals and another cable totransmit information, with additional connectors serving to connect therespective communication links to the antenna and receiver housings. Ifthe antenna and receiver are used within an existing cable network(e.g., a built-in RF-cable network as installed by the originalmanufacturer of a particular transportation means, for example, a car,airplane or boat), such an approach will require extra cable work whichis not always possible or practical.

Alternatively, two-way communication between the antenna and receiver isprovided using signals whose spectrum is concentrated in thelow-frequency portion (i.e., from 0 Hz up to 5 MHz), which isconsiderably lower than the GNSS spectrum in the range of 1.2 GHz-1.5GHZ. Such a difference in characteristic frequencies allows for a simpledivision of GNSS signals and the signals from sensors with the help ofwell-known frequency-selective techniques in the field of radioengineering. In this way, the two-way data communication between antennasensors and the navigation receiver can be made through the same RFcable as that of the transmission of the received GNSS signal from theantenna element to the receiver RF path. The use of a common RF cableallows for the use of the available cable network to connect the antennaand receiver and eliminates any possible complication in the mechanicaldesign of the antenna housing due to additional cabling/connectors, forexample.

There are a number of known GNSS antenna configurations utilizingadditional sensors, non-volatile memory and other additional informationsources/receivers inside the antenna. For example, U.S. Pat. No.8,446,984 to T. Kelin et al. describes a method of transmittingconfiguration parameters from a GNSS antenna via a RF cable usingadditional amplitude modulation of the GNSS signal as transmitted fromthe antenna module to the receiver. Signal demodulation and extractionof configuration data are performed in the receiver in the backgroundmode during routine automatic gain control (AGC) operations. Thistechnique does not require additional hardware blocks or special cabletransceivers to receive and demodulate the additional signal. However, apotential drawback of this solution is principally a low communicationrate, and the communication channel operates in one direction (i.e.,from GNSS antenna to GNSS receiver).

United States Patent Publication No. 2011/0285584 to H. Le Sagedescribes a measuring system comprising different sensors integratedinto a telecommunication antenna. Information from the sensors istransmitted to external users through a single cable. A maindisadvantage of this method is the availability of the additional cableresulting in complicating the cabling system and adding extra mechanicalconnectors to the antenna and receiver, respectively.

U.S. Pat. No. 7,212,921 to M. Jeerage describes a satellite navigationsystem wherein a measuring unit consisting of a combined GNSS antennamodule and IMU is connected to a remote GNSS receiver via a single RFcable. The GNSS signal and IMU measurements are transmitted to thereceiver via a single RF cable. The antenna's low noise amplifier (LNA)and IMU are powered from the receiver through the same cable, and thepower voltage, GNSS signal, and IMU signal differ in frequency and canbe separated by a system of filters.

Chinese Patent Application No. CN 101765787 describes an ultra-tightlycoupled GNSS-IMU system comprising an integrated antenna with built-inIMU. One potential drawback of this system is the additional cable totransmit measurements from the IMU to the remote GNSS receiver.

Chinese Patent Application No. CN 102590842 describes an integratedantenna configuration with built-in IMU which includes a transmission ofGNSS signal, IMU measurements and IMU power supply through the same RFcable. In this antenna configuration, the IMU signal is modulated fortransmission together with the GNSS signal through the RF cable.

As mentioned above, the above-described techniques have certaininefficiencies, for example, with respect to a lack of a channel totransmit data from the GNSS receiver to the GNSS antenna. As such, thismakes any synchronization of IMU measurements with the receiver's timescale, as well as, updating of firmware (FW) inside a digitalcontrolling device (which collects data from the IMU sensors) nearlyimpossible to achieve in any efficient manner.

Therefore, a need exists for an improved GNSS antenna having anintegrated antenna element in combination with a plurality of built-insources and/or receivers of additional information for exchanging theinformation and transmission of GNSS signals from the antenna element toa receiver over a single RF cable.

BRIEF SUMMARY OF THE EMBODIMENTS

In accordance with various embodiments, an improved GNSS antenna isprovided having an integrated antenna element in combination with aplurality of built-in sources of additional information and/or aplurality of devices for receiving additional information (i.e.,receivers of additional information) for exchanging the information andtransmission of GNSS signals from the antenna element to a GNSS receiverover a single RF cable. As such, “additional information”, in accordancewith the embodiments herein, is information from these various different(and independent) sources (e.g., sensors, memory, other devices, etc.)and this additional information is distinguishable from the so-called“main information” available from the antenna element of GNSS antenna inthe normal course of operation. That is, the GNSS may have built-insources that provide additional information (e.g., temperature orpressure sensors, or stored information from a memory device) and/ordevices that receive additional information (e.g., received and storedto a memory device) wherein the additional information is of the typethat is associated with the ambient conditions or physical properties,for example, in which the GNSS antenna (or other associated components)is operating in (or subject to) and which may influence such operationor other characteristics thereof.

In accordance with an embodiment, an integrated GNSS antenna is providedcomprising an antenna module to receive signals from one or more GNSSsatellites in combination with a plurality of built-in sources and/orreceivers of additional information for exchanging the information andtransmission of GNSS signals from the antenna element to a receiver overa single RF cable. The plurality of built-in sources/receivers may betightly fixed to the antenna housing or affixed internally within theantenna's housing. Further, the plurality of sources and/or receiversare, respectively, connected to a digital controlling device (e.g.,micro-controller, field programmable gate array (FPGA), or applicationspecific integrated circuit (ASIC), to name just few) which adjusts thesources/receivers and provides for an information exchange with users ofthe antenna device.

In accordance with an embodiment, two-way communication between theintegrated antenna and an external location (defined by the location ofa user and/or a remote GNSS receiver), is implemented via the same RFcable responsible for transmitting GNSS signals from the antenna moduleto the external location (e.g., the user). Electronic blocks within theintegrated antenna (e.g., LNA, digital controlling device connectioncircuits, etc.) are also powered through the same RF cable. To implementthe two-way data exchange via the RF cable, two specially configuredcable transceivers are installed, illustratively, at the opposite endsof the RF cable, in particular, one inside the antenna (i.e., a firsttransceiver) and the other in the remote receiver (i.e., a secondtransceiver).

The antenna's transceiver (i.e., the first transceiver) receives digitaldata from the digital controlling device (to which the sources/receiversof additional information are connected), converts them into an analogsignal for further transmission to the remote GNSS receiver via the RFcable. In turn, the antenna's transceiver receives analog signalstransmitted through the RF cable from the remote GNSS receiver. Thereceived analog signals are decoded into digital synchronization signalsand/or digital packets with commands and/or data further transmitted tothe digital controlling device that controls the plurality of sourcesand receivers (i.e., collectively, the additional informationsource(s)). The synchronized signals are used by the controller to tierequests to particular ones of the sources and/or receivers to the timescale of the external location (e.g., the user and/or a remote GNSSreceiver). The packets with commands and data are used by the digitalcontrolling device to control the operation mode of thesources/receivers and/or to update the FW version inside the digitalcontrolling device.

The receiver's transceiver (i.e., the second transceiver) receivesanalog information as transmitted by the antenna's transceiver via theRF cable, converts such analog information into digital data for furtherdelivery to a computational unit of the GNSS receiver through a digitalinterface for use with certain well-known navigation algorithms. Thistransceiver also receives digital synchronization signals and digitalpackets with commands and/or data from the GNSS receiver's computationunit, and converts such commands and/or data into an analog signal andfor transmission to the remote integrated antenna via the RF cable.

In accordance with the embodiment, analog signals are generated by bothtransceivers (as connected to the opposite ends of the RF cable) and areconcentrated in the low-frequency band area as contrasted with thehigher frequency band/spectrum area of GNSS signals. Splitting of theGNSS signal (as directed from the antenna to the GNSS receiver), thepower supply signal of the integrated antenna (from the GNSS receiver tothe antenna) and the analog communication signal (i.e., the two-waycommunications signal) is implemented by well-known frequency-selectivereception techniques. If the low-frequency analog spectra transmittedfrom the GNSS receiver to the antenna and from the antenna to the GNSSreceiver, respectively, overlap then the information exchange betweenthe antenna and the GNSS receiver is made via a half-duplex mode.Alternatively, if the spectra of these signals does not overlap and theattenuated low-frequency signal received from the remote transceiver canbe isolated against the strong low-frequency signal transmitted by thetransceiver, then the information exchange between the antenna and theGNSS receiver can be made in a full duplex mode.

In accordance with a further embodiment, the integrated GNSS antenna hasone or more atmospheric sensors for measuring pressure, humidity and/orambient temperature directly at the antenna location thereby providingfurther sources of additional information. To facilitate the necessarycontact of the sensor elements with the surrounding environment (e.g.,ambient air), in accordance with this embodiment, the antenna's housingis provided with one or more openings.

In accordance with a further embodiment, the integrated antenna utilizesone or more inertial sensors for measuring angular velocity vectorcomponents and antenna specific acceleration vector components. Further,in accordance with this embodiment, a random combination of differentsensors are connected such that their measurements are read by thedigital controlling device synchronously in the remote GNSS receiver'stime scale.

In addition to the set of sensors measuring physical parameters asdetailed above, in accordance with an embodiment, the antenna may alsocontain a non-volatile memory (e.g., reprogrammed or once-programmedmemory) where certain data configurations are available (for example,serial antenna number, antenna type, sensor nomenclature, sensorcoordinates relative to antenna PC, etc.) and/or the retention ofcharacteristic operating parameters of the given antenna unit and itsset of sensors as a result of factory calibration. In accordance withthe embodiment, non-volatile memory modules are connected to the samedigital controlling device as the sensors and can be read or re-writtenaccording to commands from a remote GNSS receiver which is asynchronouswith the GNSS receiver's time scale.

These and other advantages of the embodiments will be apparent to thoseof ordinary skill in the art by reference to the following detaileddescription and the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1A is a system diagram illustrating the transmission of additionalinformation from an integrated GNSS antenna to a remote GNSS receivervia a RF cable in accordance with an embodiment;

FIG. 1B is a functional block diagram of the GNSS receiver and GNSSantenna, respectively, as shown in FIG. 1A in accordance with anembodiment;

FIG. 2 is a graph of the relative position of spectra of an antennapower signal, and a communication signal between a GNSS antenna and aGNSS receiver in accordance with an embodiment;

FIG. 3 is a functional block diagram of a cable transceiver inaccordance with an embodiment;

FIG. 4 is a diagram showing an integrated antenna for a dual-antennapositioning system in accordance with an embodiment;

FIG. 5 is a diagram showing an integrated antenna for a multi-antennapositioning system in accordance with an embodiment; and

FIG. 6 shows a flowchart of illustrative operations for a GNSS antennaconfigured in accordance with an embodiment.

DETAILED DESCRIPTION

In accordance with various embodiments, an improved GNSS antenna isprovided having an integrated antenna element in combination with aplurality of built-in sources and receivers of additional informationfor exchanging the information and transmission of GNSS signals from theantenna element to a GNSS receiver over a single RF cable. As notedpreviously, the additional information, in accordance with theembodiments, is information from these various different (andindependent) sources (e.g., sensors, memory, other devices, etc.) andthis additional information is distinguishable from the main informationavailable from the antenna element of GNSS antenna in the normal courseof operation. That is, the GNSS may have built-in sources that provideadditional information (e.g., temperature or pressure sensors, or storedinformation from a memory device) and/or devices that receive additionalinformation (e.g., received and stored to a memory device) wherein theadditional information is of the type that is associated with theambient conditions or physical properties, for example, in which theGNSS antenna (or other associated components) is operating in (orsubject to) and which may influence such operation or othercharacteristics thereof.

FIG. 1A is a system diagram illustrating the transmission of additionalinformation from an integrated GNSS antenna to a remote GNSS receivervia a RF cable in accordance with an embodiment. FIG. 1B is a functionalblock diagram of the GNSS receiver and GNSS antenna, respectively, asshown in FIG. 1A in accordance with an embodiment. For ease ofdiscussion and understanding of the embodiments, these figures will benow be discussed together.

As shown, navigation system 130 comprises a separate remote GNSSreceiver 100 and an integrated GNSS antenna 101 with a plurality ofsources (e.g., sensors 108 and 111, and non-volatile memory 109) ofadditional information being exchanged with GNNS receiver 100 through RFcable 102. Via this same cable (i.e., RF cable 102), a GNSS signalreceived by antenna element 103 is transmitted from GNSS antenna 101 toGNSS receiver 100, and a direct voltage is supplied to the electronicblocks of the integrated antenna (i.e., from GNSS receiver 100 to GNSSantenna 101).

Using ground plane 104, antenna element 103 is separated from thesurface upon which the electronic blocks are mounted. A low-noiseamplifier (LNA) 105 is protected by shield 106, and digital controllingdevice 107, a set of IMU sensors 108, non-volatile memory 109 are allprotected by shield 110 (which is separate therefrom). A set of sensors111 are provided (such sensors being of one single type or a variety ofdifferent sensor types) and can be electronic blocks of the integratedantenna. If certain sensitive elements of the set of sensors 111 need adirect contact with environment, such a contact can be provided by oneor more orifices 112 cut into housing 123 of integrated GNSS antenna101.

Digital controlling device 107 (e.g., a microcontroller, FPGA, ASIC, orsimilar type of device) reads information from sensors 108, 111 and/orfrom nonvolatile memory 109 and transmits the information throughdigital interface 122 in the antenna's transceiver 113. The informationread from these sensors and/or memory, for example, is the additionalinformation which, in accordance with the embodiments, is informationthat is distinguishable from (and different than) the main informationavailable from antenna element 103 of GNSS antenna 101 in the normalcourse of operation. Transceiver 113 converts the digital data fromdigital controlling device 107 into an analog signal which is furthertransmitted in remote GNSS receiver 100 via RF cable 102. Transceiver113 also receives the analog signal from remote GNSS receiver 100 andconverts the analog signal into digital data for further delivery todigital controlling device 107. Such received data can be, for example,a sensor's enquiry signals synchronized with the time scale associatedwith GNSS receiver 100, integrated antenna control commands, data readcommands to obtain integrated antenna status, FW updating commandsassociated with digital controlling device 107, to name just a few datatypes. Transceiver 113 is connected to internal RF cable 114 coupled toantenna element 103 with external RF connector 115 on the housing of theGNSS antenna 101.

Inside GNSS receiver 100 there is computation unit 124 coupled totransceiver 116 which is connected to internal RF cable 117 switching RFconnector 118 of the receiver's housing (to which RF cable 102 isconnected) to the input of RF part 119 of GNSS receiver 100. The GNSSreceiver's transceiver (i.e., transceiver 116) converts a digital signalfrom digital part 120 of GNSS receiver 100 via two-way digital interface121 into an analog signal further delivered via RF cable 102. The GNSSreceiver's transceiver (i.e., transceiver 116) also receives the analogsignal transmitted by antenna's transceiver 113 from RF cable 102, andconverts the analog signal into a digital signal for delivery to digitalpart 120 through digital interface 121.

There are three signals present in RF cable 102 during operation ofnavigation system 130: (i) the direct voltage to supply of the remoteantenna, (ii) the analog signal exchanged between the antenna (e.g.,GNSS antenna 101) and receiver (e.g., GNSS receiver), and (iii) a GNSSsignal. The relative location of the spectra of these signals is shownin FIG. 2 which is a graph of the relative position of spectra of anantenna power signal, and communication signal between an antenna and aGNSS receiver in accordance with an embodiment. The spectrum 201 of thedirect voltage signal transmitted from the GNSS receiver 100 to GNSSantenna 101 lies on the frequency of 0 Hz. This signal is separated inGNSS antenna 101 by a narrow-band low-frequency filter with, forexample, amplitude-frequency characteristic (AFC) 202 as shown in graph200 of FIG. 2.

Spectrum 203 of the analog signal is transmitted by the antenna'stransceiver 113 and spectrum 206 of the analog signal transmitted byGNSS receiver's transceiver 116 are concentrated in the low-frequencyarea without signal overlapping on the frequency of 0 Hz occupied bydirect voltage signal 201. The antenna's transceiver signal withspectrum 203 is isolated by the receiver's transceiver 116 by a bandpassfilter having AFC 204, for example. The antenna transceiver signal 116with spectrum 206 is isolated by the antenna's transceiver 113 by abandpass filter having AFC 205, for example.

Spectra 203 and 206 can be randomly located on the frequency axisrelative to each other. If spectra 203 and 206, respectively, do notoverlap and bandpass filters having AFC 204 and 205, respectively, canisolate the weakened received signal due to suppressing its owntransmitted signal, a two-way data exchange between GNSS receiver 100and GNSS antenna 101 can be accomplished in a full duplex mode.Otherwise, if spectra 203 and 206 overlap or the bandpass filter of thereceiving transceiver cannot suppress its own transmitted signal, thetwo-way data exchange between GNSS antenna 101 and GNSS receiver 100 isimplemented in a half-duplex mode. Further, GNSS spectrum 207transmitted from GNSS antenna 101 to GNSS receiver 100 is considerablydistant from the low-frequency area occupied by spectra 201, 203, 206,respectively. This signal is isolated in RF-part 119 of GNSS receiver100 using a bandpass filter having AFC 208, for example.

FIG. 3 is a functional block diagram of a cable transceiver inaccordance with an embodiment. As shown, cable transceiver 301 can beconfigured as antenna's transceiver 113 or receiver's transceiver 116 byselecting the corresponding firmware/software settings. Transceiver 301is switched to RF cable 302 which in turn is RF cable 114 (as shown inFIG. 1B), if the settings of transceiver 301 correspond to thespecification of transceiver 113, or which in turn is RF cable 117 (asshown in FIG. 1B), if the settings of transceiver 301 match thespecification of transceiver 116. The direct voltage signal transmittedvia RF cable 302 is separated in transceiver 301 using a narrow-bandlow-frequency filter 303 having AFC 202, for example. This signal isused to power electronic blocks (via power supply 310) inside integratedGNSS antenna 101. When transceiver 301 is configured according to thespecification of transceiver 116, this signal is turned off.

Reception of the analog data exchange signal from RF cable 302 isaccomplished via receiving bandpass filter 304. The analog data exchangesignal is transmitted to RF cable 302 from the output of a generatingbandpass filter 305. If transceiver 301 is adjusted according to thespecification of the antenna's transceiver 113, the bandpass filter 304will have AFC 205, for example, and bandpass filter 305 will have AFC203, for example. If transceiver 301 is adjusted according to thespecification of the receiver's transceiver 116, then bandpass filter304 will have AFC 204, for example, and bandpass filter 305 will haveAFC 206, for example.

Modulator/demodulator 307 receives a filtered analog signal from theoutput of bandpass filter 304, extracts the received information fromsuch filtered analog signal which is further transmitted to the user viadata exchange digital interface 308. The modulator/demodulator 307 alsoreceives digital information from interface 308 and converts suchdigital information into an analog signal whose spectrum is coordinatedwith generating filter 305. Once the analog signal has been converted,it is delivered to the input of filter 305, and from its output it isdelivered to RF cable 302. If transceiver 301 matches the specificationof the transceiver 113, then digital interface 308 corresponds todigital interface 122. If transceiver 301 matches the specification oftransceiver 116, then digital interface 308 corresponds to digitalinterface 121.

FIG. 4 is a diagram 400 showing an integrated antenna for a dual-antennapositioning system in accordance with an embodiment. Integrated GNSSantenna 101 has IMU 108 which operates within dual-antenna navigationsystem 130 (see also, FIG. 1). Measurements of angular velocity vectorand specific acceleration vector made by IMU sensors are brought to thecorresponding orthogonal Measurement Frame 401 which is tightly coupledto the housing of GNSS antenna 101. For the sake of clarity, the originof MF coordinates is in PC 402 of GNSS antenna 101. Phase center 403 ofa second GNSS antenna 404 is shifted by base vector 405 relative tophase center 402 of GNSS antenna 101 (i.e., the first antenna). As such,GNSS antennas 101 and 404 are connected to dual-antenna GNSS receiver406 by RF cables 407 and 408, respectively. RF cable 407 is connected toan antenna connector of dual-antenna receiver 406 that is switched tothe receiver's transceiver 116 inside of receiver 406.

After the dual-antenna system is installed onto the target platform inGNSS receiver 406, coordinates of base vector 405 drawn from PC 402towards PC 403 are stored relative to MF 401. For example, Cartesiancoordinates of vector (i.e., X, Y, Z coordinates) or sphericalcoordinates of its end (i.e., vector length D, angle (φ1, and angle φ2)can serve as such coordinates. These coordinates can be used tocoordinate measurements of IMU 108 with GNSS measurements of GNSSantennas 101 and 404 in multiplexing the inertial and satellitenavigation systems in FW of dual-antenna receiver 406.

FIG. 5 is a diagram 500 showing an integrated antenna for amulti-antenna positioning system in accordance with an embodiment. Asshown, the diagram is of the illustrative operation of integrated GNSSantenna 101 in a multi-antenna system wherein the total number of GNSSantennas is greater than or equal to N≥3. In such a system integratedGNSS antenna 101 is connected to an antenna connector of multi-antennareceiver 501 to which the receiver's transceiver 116 is switched. Aftersuch a system is installed onto the target platform in GNSS receiver501, coordinates of all base vectors 502 drawn from PC 402 of integratedGNSS antenna 101 towards phase centers of each N−1 additional GNSSantennas 503. These coordinates are used to coordinate measurements ofIMU 108 with GNSS measurements of integrated GNSS antenna 101 and N−1additional GNSS antennas 503 when the inertial and satellitenavigational systems are multiplexed in FW of multi-antenna receiver501.

FIG. 6 shows a flowchart of illustrative operations 600 for a GNSSantenna configured in accordance with an embodiment. In particular,receiving at least one GNSS signal at step 610, amplifying the at leastone GNSS signal at step 620, and receiving additional information from aplurality of sources and/or a plurality of devices for receivingadditional information at step 630, as detailed herein above. Inparticular, the additional information, in accordance with theembodiment, from these various different (and independent) sources(e.g., sensors, memory, other devices, etc.) is distinguishable from(and different than) the main information available from the antennaelement of GNSS antenna in the normal course of operation. Further, atstep 640, exchanging a two-way communication between the plurality ofsources and a receiver (and corresponding user thereof) via an RF cable,and synchronizing, with a specific time scale, particular ones of theadditional information from the plurality of sources and/or theplurality of receiving devices at step 650. At step 660, co-processing aset of GNSS measurements together with the synchronized additionalinformation to produce a GNSS positioning solution. As such, theaforementioned operations are such that the GNSS antenna may havebuilt-in sources that provide additional information (e.g., temperatureor pressure sensors, or stored information from a memory device) and/ordevices that receive additional information (e.g., received and storedto a memory device) wherein the additional information is of the typethat is associated with the ambient conditions or physical properties,for example, in which the GNSS antenna (or other associated components)is operating in (or subject to) and which may influence such operationor other characteristics thereof.

It should be noted that for clarity of explanation, the illustrativeembodiments described herein may be presented as comprising individualfunctional blocks or combinations of functional blocks. The functionsthese blocks represent may be provided through the use of eitherdedicated or shared hardware, including, but not limited to, hardwarecapable of executing software. Illustrative embodiments may comprisedigital signal processor (“DSP”) hardware and/or software performing theoperation described herein. Thus, for example, it will be appreciated bythose skilled in the art that the block diagrams herein representconceptual views of illustrative functions, operations and/or circuitryof the principles described in the various embodiments herein.Similarly, it will be appreciated that any flowcharts, flow diagrams,state transition diagrams, pseudo code, program code and the likerepresent various processes which may be substantially represented incomputer readable medium and so executed by a computer, machine orprocessor, whether or not such computer, machine or processor isexplicitly shown. One skilled in the art will recognize that animplementation of an actual computer or computer system may have otherstructures and may contain other components as well, and that a highlevel representation of some of the components of such a computer is forillustrative purposes.

The foregoing Detailed Description is to be understood as being in everyrespect illustrative and exemplary, but not restrictive, and the scopeof the invention disclosed herein is not to be determined from theDetailed Description, but rather from the claims as interpretedaccording to the full breadth permitted by the patent laws. It is to beunderstood that the embodiments shown and described herein are onlyillustrative of the principles of the present invention and that variousmodifications may be implemented by those skilled in the art withoutdeparting from the scope and spirit of the invention. Those skilled inthe art could implement various other feature combinations withoutdeparting from the scope and spirit of the invention.

What is claimed is:
 1. A transceiver comprising: a modulator/demodulatorthat receives (i) digital data, the digital data comprising additionalinformation from particular sources of a plurality of sources, andconverts the digital data into a converted analog signal and (ii) ananalog signal and decodes the analog signal into digital synchronizationsignals; and an output that establishes a two-way data communication,over an RF cable, between a GNSS antenna associated with the transceiverand a GNSS receiver and for transmitting the converted analog signal andthe digital synchronization signals over the RF cable such that the GNSSantenna synchronizes the particular sources of the plurality of sourceswith a time scale associated with at least one location external to theGNSS antenna via the RF cable and the transceiver.
 2. The transceiver ofclaim 1 wherein the plurality of sources includes at least one inertialsensor, the inertial sensor measuring at least one of an accelerationvector and an angular velocity vector.
 3. The transceiver of claim 1wherein the plurality of sources includes at least one atmosphericsensor, the atmospheric sensor measuring at least one of a pressure, ahumidity level, and an ambient temperature at a point of receiving theGNSS signal.
 4. The transceiver of claim 1 wherein the plurality ofsources include at least one magnetic sensor, the magnetic sensormeasuring at least one magnetic field vector.
 5. The transceiver ofclaim 1, further comprising: a first bandpass filter that receives theanalog signal.
 6. The transceiver of claim 5 further comprising: asecond bandpass filter that receives and filters the converted analogsignal prior to transmission thereof across the RF cable.
 7. Thetransceiver of claim 6 wherein the first bandpass filter has a firstamplitude-frequency characteristic (AFC) and the second bandpass filterhas a second AFC, the first AFC and the second AFC having differentvalues.
 9. The transceiver of claim 1 wherein the two-way datacommunication is a full duplex mode communication.
 10. The transceiverof claim 1 wherein the two-way data communication is a half-duplexcommunication.
 11. The transceiver of claim 6 further comprising: anarrow-band low frequency filter for receiving, across the RF cable, adirect voltage signal.
 12. The transceiver of claim 11 wherein thedirect voltage signal powers one or more electronic blocks associatedwith the GNSS antenna.
 13. The transceiver of claim 1 wherein thetransceiver communicates, across the RF cable, with another transceiverassociated with the GNSS receiver.
 14. The transceiver of claim 13wherein the GNSS antenna is connected to an antenna connector of amulti-antenna receiver to which the another transceiver is switched. 15.The transceiver of claim 1 wherein the transceiver further comprises: acoupling with an RF connector for connecting the transceiver with the RFcable.
 16. A method of operating a transceiver, the method comprising:receiving by the transceiver (i) digital data, the digital datacomprising additional information from particular sources of a pluralityof sources, and converting the digital data into a converted analogsignal and (ii) an analog signal and decoding the analog signal intodigital synchronization signals; and establishing a two-way datacommunication over a RF cable between a GNSS antenna associated with thetransceiver and a GNSS receiver, and transmitting the converted analogsignal and the digital synchronization signals over the RF cable suchthat the GNSS antenna synchronizes the particular sources of theplurality of sources with a time scale associated with at least onelocation external to the GNSS antenna via the RF cable and thetransceiver.
 17. The method of claim 16 wherein the plurality of sourcesincludes at least one inertial sensor, the inertial sensor measuring atleast one of an acceleration vector and an angular velocity vector. 18.The method of claim 16 wherein the plurality of sources includes atleast one atmospheric sensor, the atmospheric sensor measuring at leastone of a pressure, a humidity level, and an ambient temperature at apoint of receiving the GNSS signal.
 19. The method of claim 16 whereinthe plurality of sources include at least one magnetic sensor, themagnetic sensor measuring at least one magnetic field vector.
 20. Themethod of claim 16 further comprising: receiving, across the RF cable, adirect voltage signal; and powering one or more electronic blocksassociated with the GNSS antenna.